XML 93 R72.htm IDEA: XBRL DOCUMENT v3.8.0.1
STOCKHOLDERS' EQUITY - Compensation Plan (Details)
$ / shares in Units, $ in Millions
 1 Months Ended 12 Months Ended
Jan. 31, 2015
MXN / shares
Jan. 31, 2015
$ / shares
Dec. 31, 2017
USD ($)
$ / shares
shares
Dec. 31, 2016
USD ($)
$ / shares
shares
Dec. 31, 2015
USD ($)
$ / shares
shares
Dec. 31, 2010
MXN / shares
Dec. 31, 2010
$ / shares
Non-controlling interest              
Investment shareholders' interest in Peruvian Branch (as a percent)     0.71%        
Employee Stock Purchase 2010 Plan              
Information related to compensation cost              
Purchase price for initial subscription (in dollars per share) | (per share)           MXN 26.51 $ 1.28
Percentage of title acquired by employee in every two years on shares paid in previous two years     50.00%        
Period of plan     8 years        
Ratio of bonus shares granted to participant     0.1        
Stock based compensation expense | $     $ 0.6 $ 0.6 $ 0.6    
Unrecognized compensation expense | $     $ 0.2 $ 0.8 $ 1.4    
Stock award activity, Shares              
Outstanding shares at the beginning of the period | shares     1,401,096 2,227,582      
Exercised (in shares) | shares     (7,433) (826,486)      
Outstanding shares at the end of the period | shares     1,393,663 1,401,096 2,227,582    
Unit Weighted Average Grant Date Fair Value              
Outstanding shares at the beginning of the period (in dollars per share) | $ / shares     $ 2.05 $ 2.05      
Exercised (in dollars per share) | $ / shares     2.05 2.05      
Outstanding shares at the end of the period (in dollars per share) | $ / shares     2.05 $ 2.05 $ 2.05    
Employee Stock Purchase 2015 Plan              
Information related to compensation cost              
Purchase price for initial subscription (in dollars per share) | (per share) MXN 38.44 $ 1.86 $ 1.86        
Percentage of title acquired by employee in every two years on shares paid in previous two years     50.00%        
Period of plan     8 years        
Ratio of bonus shares granted to participant     0.1        
Stock based compensation expense | $     $ 0.6 $ 0.6 $ 0.4    
Unrecognized compensation expense | $     $ 3.2 $ 3.8 $ 4.4    
Stock award activity, Shares              
Outstanding shares at the beginning of the period | shares     2,540,223 2,656,386      
Exercised (in shares) | shares     (247,103) (116,163)      
Outstanding shares at the end of the period | shares     2,293,120 2,540,223 2,656,386    
Unit Weighted Average Grant Date Fair Value              
Outstanding shares at the beginning of the period (in dollars per share) | $ / shares     $ 2.63 $ 2.63      
Exercised (in dollars per share) | $ / shares     2.63 2.63      
Outstanding shares at the end of the period (in dollars per share) | $ / shares     $ 2.63 $ 2.63 $ 2.63